General arrangement for projector

ABSTRACT

A projector having a molded plastic outer case which is supported by a curved steel stand which also serves as an elevating device and carrying handle. The projector can be tilted simply by sliding it up on the curved stand and locking it with two knobs. An electric lamp is mounted at a center location within the case and a pair of heat dissipating baffle plates are positioned on opposite sides of the lamp. A cover is positioned over the lamp and baffle plates to direct the cooling air rising adjacent the lamp toward the rear of the projector. A film advance mechanism is housed in the case and includes an arm which engages the film sprocket holes only during the advancing operation.

United States Patent 1 Martinez 1 Aug. 7, 1973 GENERAL ARRANGEMENT FORPROJECTOR [75] lnventor: Eugene Martinez,

lrvington-on-Hudson, NY.

[22] Filed: Feb. 11, 1970 [21] Appl. No.: 10,346

Related U.S. Application Data [63] Continuation of Ser. No. 715,621,March 25, 1968,

Pat. N0. 3,520,599.

3,124,039 3/1964 Anderson 353/95 FOREIGN PATENTS OR APPLICATIONS1,199,664 12/1959 France 353/61 229,243 (1/1924 Great Britain 3.53/95683,131 10/1939 Germany 353/57 Primary Examiner-Louis R. PrinceAssistant Examiner-A. J. Mirabito Attorney-J. B. Fclshin 57 ABSTRACT Aprojector having a molded plastic outer case which is supported by acurved steel stand which also serves as an elevating device and carryinghandle. The projector can be tilted simply by sliding it up on thecurved stand and locking it with two knobs. An electric lamp is mountedat a center location within the case and a pair of heat dissipatingbaffle plates are positioned on opposite sides of the lamp. A cover ispositioned over the lamp and baffle plates to direct the cooling airrising adjacent the lamp toward the rear of the projector. A filmadvance mechanism is housed in the case and includes an arm whichengages the film sprocket holes only during the advancing operation.

15 Claims, 9 Drawing Figures PATENIEB 7W5 SHEEI1BF4 INVENTOR alas/v5MAlf/NIZ ATTORNEY FIG 2 GENERAL ARRANGEMENT FOR PROJECTOR Thisapplication is division of, application Ser. No. 715,621, filed Mar. 25,1968, for Projector, now U.S. Pat. No. 3,520,599.

BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to asimple, safe and silent projector for individual and small groupinstruction. In the illustrated embodiment, the projector is adapted foruse with conventional filmstrips of the type commonly used byeducational institutions as a supplement to reg ular teaching methods.Thepotential for this system has never been fully realized sinceconventional projectors are complex, expensive, and dangerous whenoperated by small children.

In a broad sense, this invention relates to a filmstrip projector havinga molded plastic case enclosing the projection apparatus. A stand foradjustably supporting the case between a horizontal and an inclinedposition is attached to each side by means of an integral cylindricalear adjacent the rear of the case and a clamping means at the front ofthe case. The stand comprises a pair of rods positioned on oppositesides of the case, each rod being rotatably mounted about thecylindrical ear. The stand also includes a segment forming an arc of acircle about the cylindrical ear and which is releasably secured by theclamping means to the front of the case. By releasing the clampingmeans, the inclination of the projector relative to the stand may beeasily varied by merely rotating the projector about the axes of the twocylindrical ears.

The case of the projector generally comprises a pair of substantiallyparallel side walls, upper and bottom walls having air vents therein,and front and rear walls. An electric lamp is mounted at a centerlocation within the case, and a pair of parallel baffle plates aremounted on opposite sides of the lamp. An inverted U- shaped cover ispositioned above the lamp and baffle plates, the cover having aninclined upper transverse surface for deflecting the air rising adjacentthe lamp to the vent holes at the rear of the case upper wall.

The projector also includes a film advance mechanism which incorporatestwo closely spaced parallel plates defining a passageway for thefilmstrip through the projector. One of the plates has an apertureopening to the area occupied by the sprocket holes of the film and whichextends in the direction of film advance. A cam is positioned on oneside of this plate adjacent the aperture and also extends in thedirection of film advance. An advancing slider is mounted on the platefor translation between a rear and forward position, the slider havingan elongated extension with a cam follower at the end thereof which isadapted to engage the cam when the slider is translated between the rearand the forward positions. A transverse arm is also positioned at theend of the extension such that when the cam follower engages the cam,the arm is projected through the aperture and into engagement with thesprocket holes of the film. Upon continued translation, the film isadvanced a distance corresponding to the length of the cam.

a projector which may be easily and quickly set-up, and wherein the bodyof the projector is supported by a curved steel stand that doubles as anelevating device and carrying handle. The projector can be tilted up to30 elevation simply by sliding it up the steel stand and locking it withtwo knobs. Thus, the use of books and other makeshift props under theprojector is eliminated.

It is also an object of this invention to provide a projector whichincorporates a frame advance mechanism which is completely free of thefilm when it is not being actuated. Thus, a child could pull as hard aspossible on the film up or down, and the film will slide freely,undamaged in either direction.

It is still another object to provide a projector wherein the outerwalls stay cool during operation without the need for a cooling fan. Adouble wall construction is utilized to dissipate the heat of the lampby the normal convection currents which pass the walls on each side ofthe lamp. The elimination of the cooling fan thus avoids the danger fromrapidly turning blades. Also, the operation is absolutely silent whichis a necessity when the projector is used in close proximity of astudent.

These and other objects and advantages of the present invention willreadily become apparent to one skilled in the art from the followingdetailed description.

Brief Description of the Drawings FIG. 1 is a perspective view showingthe projector case and its associated stand;

FIG. 2 is a horizontal sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a vertical sectional view taken along the line 33 of FIG. 2;

FIG. 4 is a vertical sectional view taken along the line 4-4 of FIG. 2;

FIG. 5 is a fragmentary front view of the back plate and its associatedadvancing slider;

FIG. 6 is a fragmentary rear view of the back plate and its associatedadvancing slider; FIG. 7 is an enlarged sectional view taken along thelines 7-7 of FIG. 6;

FIG. 8 is a view similar to FIG. 7 showing the cam follower engagedduring the film advance operation; and

FIG. 9 is a view taken along the line 9-9 of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, aprojector incorporating the features of the present invention isdesignated generally at 10. The outer case of the projector comprises anupper section 11 and a lower section 11 which are joined by suitablebolts 12 to form an enclosure for the projection apparatus. The case maybe described as a somewhat rectangular box having two parallel sidewalls 13, and upper wall 14, a bottom wall 15, a front end 16, and arear end 17.

As will become apparent from the following description, the two casesections 11 and 11 are themselves identical in configuration, a factwhich greatly contributes to cost reduction and simplicity of design.The case is preferably formed from a molded high impact thermoplasticmaterial, such as the acrylonitrile butadiene styrene thermoplasticresin Cycolac, produced by the Marbon Chemical Division of Borg-WarnerCorporation. The case is suitably shaped to provide means for attachingthe various internal projector components. The upper wall 14 is providedwith a plurality of air vents l8 and 18' (not FIGS. 3 and 4) while thelower wall has similar vents 19 and 19'.

Viewing FIG. 2, it will be seen that the internal projection apparatusincludes as essential elements an electric lamp assembly 20, a rearaccess door assembly 27, a lens condenser assembly 40, a film guide andadvance mechanism 50, and a forward focusing lens 80.

The lamp assembly 20 includes a standard projector lamp 2] having abayonet base for mounting in a conventional socket 22. The socket isconnected to an appropriate electrical wire (not shown), and is suitablymounted in the case by means of a strap 23.

A pair of baffle plates are mounted on opposite sides of the lamp ingenerally parallel and spaced relation to the side walls 13. The plates25, which may be formed from extruded aluminum, include a plurality ofvertically extending transverse ribs 26 which are designed to facilitateheat dissipation and which may be positioned either on one or both sidesof the plate.

Access to the lamp 21 for replacement is provided by the rear accessdoor assembly 27. As seen in FIG. 3, the assembly 27 includes a back 28which pivots about the hinge pin 29. The back 28 is releasably securedat its upper end to the case by a Nylon screw 30 which engages a sheetmetal nut 31 clipped to the back. Thus, upon withdrawal of the screw 30,the back 28 swings to a generally horizontal position for easy access tothe lamp.

The back 28 also retains a pair of rear baffle plates 25 which aredesigned for alignment with the baffle plates 25 when the back isclosed. The baffle plates 25' may include transverse ribs 26 fordissipating heat in a manner similar to the ribs 26. A back reflector32, which preferably has a chromed surface, is secured to the forwardend of the plates 25 and is designed to reflect the light from the lamp21 through the lens condenser assembly. The back 28 may also include anaperture 33 for an electric cord, as well as a switch 34.

A cover 36, having a generally inverted U-shape in cross section, ispositioned above the lamp 2] and baffle plates 25 for the purpose ofdirecting the flow of cooling air. The cover 36, which may be made fromsheet metal, includes an upper transverse surface 37 and two paralleldepending side edges 38 (FIG. 4) which are generally aligned in adirection parallel to the baffle plates 25. In the embodiment shown, theedges 38 extend downwardly to a point adjacent the bottom of the plates25 to overlie and substantially enclose the entire lamp assembly. Itshould be understood, however, that the side edges 38 could be designedto extend only to the top portion of the baffle plates 25, or to anyintermediate position therealong without impairment of the coolingeffect. If the side edges 38 extend only to the top of the plates, theedges may also be designed to lie in the same plane as the plates ratherthan lying outside of this plane as shown in FIG. 4.

Positioned immediately above the lamp 21 is a light deflector 39 whichis suitably mounted to the upper section 11 of the case. The deflector39 serves to prevent the bright light of the lamp from being reflectedthrough the openings 18' by the transverse surface 37.

Viewing FIG. 4, it will be apparent that there exist in the presentdesign two independent air passages for dissipating the heat generatedby the lamp. In the first and primary passage (designated by the solidarrows in FIGS. 3 and 4), the air which initially enters through thelower air vents 19 and 19 passes immediately adjacent to the lamp 21within the area defined by the side edges 38 of the cover, the backreflector 32 and the condenser lens assembly 40. The air is warmed bycontact with these surfaces (as well as the baffle plates 25) andcontinues to rise until it reaches the transverse surface 37 which isinclined toward the rear of the case to direct the flow through theupper vents 18 (note FIG. 3). By this arrangement, the warm air isdirected away from the film as well as the areas which come in contactwith the operators hands. It will be noted that if the side edges 38extend only to the top of the plates 25, the plates themselves willserve as the boundary for the primary passage.

In the secondary cooling system (designated by the broken arrows), aportion of the air entering through the lower vents l9 and 19 passesalong the wall formed by the outside surface of the side edges 38 to theupper vents 18. This current of air serves to insulate the side walls 13of the case from the warm elements of the projector such that the sidewalls 13 remain cool and may be touched without danger of burning.

The lens-condenser assembly 40 includes a heat filter 41, a meniscuscondenser 42, and a bi-convex condenser 43 which are aligned in thedirection of light projection. A suitable frame 44 is designed to retainthe three elements of this assembly within the case.

The film 51 is designed to be inserted through a passageway in the filmadvance assembly defined by a back plate 52 and a front plate 53, (noteFIGS. 2-3). The two plates may be molded from a high strength, heatresistant plastic material such as the polyamide resin Zytel, which issold by DuPont. They are mounted in the case by a conventional structurewhich has not been illustrated in detail herein. To facilitate retentionof the film 51 adjacent the outer ends of the passage way, asemi-circular recess 45 may be formed in the case, (note FIG. 3).

As seen in FIGS. 5-6, the film passageway across the back plate 52includes a vertical channel defined by the edge abutments 54 and 54'which guide the film 51 past a rectangular opening 55. The opening 55serves to frame the light emanating from the lamp 21 such that when theindividual fllm image is aligned with the opening, the projected picturewill be properly framed on the screen. The channel may also incorporatea finger 46 on either side of the opening 55 (see also FIG. 2)projecting into said channel to reduce the amount of transverseclearance in the passageway at the point of projection and therebyprevent inadvertent changes of focusing, and also to prevent the filmfrom moving longitudinally while arms 72 are not in the sprocket holes.

The back plate 52 further includes a transversely directed side arm 56positioned along each vertical edge, the arms having a cut-out 57 in theupper portion thereof. A vertical slot 58 is positioned in the body ofthe plate 52 on each side of the opening 55, and an aperture 59 ispositioned below the opening 55 such that it opens to the area of thesprocket holes of the film 51. A cam 60 is positioned on the side of theplate 52 opposite the film 51 and in general alignment with the aperture59 but in spaced relation thereto, see FIGS. 7-9. The cam 60 isbifurcated (FIG. 9) and includes a forward camming surface 61 and a rearcamming surface 62.

When the back plate 52 is mounted in the case, it will be seen in FIGS.1 and 3 that the side arms 56 are positioned in appropriate slots in thecase side wall 13 such that the arms are substantially flush with theouter surfaces of the walls. This structure gives rise to a pleasingappearance as well as increased rigidity.

An advancing slider member 65 is associated with the back plate 52 tocomplete the film advance mechanism. The member 65 includes oppositelyextending finger engaging surfaces 66 which are designed to pass throughthe cut-outs 57, such that the member is retained to the plate 52. Themember 65 is also retained by two longitudinal shoulders 67 which aredesigned to be received in the slots 58 of the plate. The mid-portion ofthe member comprises a cross bar 68 from which a longitudinal extension69 projects toward the aperture 59 and cam 60. The lower end of theextension 69 is generally T-shaped in cross section, the two outerextemities of the upper portion (as seen in FIG. 9) being a cam follower71 and the remaining portion being a transverse arm 72 which is directedtoward the aperture 59.

During the film advance operation, the member 65 is translated between arear (rest) and forward (actuated) position, (note FIG. 6). The memberis controlled and guided during this translation by the interactionbetween the surfaces 66 and cut-outs 67, as well as between theshoulders 67 and slots 58. It will be seen that the shoulders 67 limitthe extent of the translation in both directions by engaging the ends ofthe slots 58.

As the member advances to the forward position, the cam follower 71 ofthe extension 69 engages the forward camming surface 61. This in turncauses the transverse arm 72 to pass through the opening 59 and engagethe sprocket holes of the film 51, (note FIGS. 7-8). Upon continuedtranslation, the follower 71 advances the film until the bottom end ofthe cam 60 is reached, at which point the arm 72 releases the film andwithdraws through the aperture 59.

The member 65 and plate 52 may have an interconnecting spring 73 toautomatically return the member to its rear position. In the illustratedembodiment, the member includes a groove 74 along the back surface ofthe cross bar 68 to provide a clearance for the spring 73.

Upon translation of the member from its forward to its rear position,the follower 71 engages the rear camming surface 62 such that the arm 72will be completely removed from the aperture 59 during the returnmovement. The inherent resilience of the extension 69 providessufficient flexibility to permit the required transverse movement of thearm 72.

It will be apparent that by properly determing the length of the cam 60(designated D in FIG. 6), the film 51 can be made to sequentiallyadvance a predetermined distance. By design, this distance willcorrespond to the distance between the individual frames on the film 51such that upon actuation of the member 65, the film will advance to thenext picture frame without further adjustment. It will also be seen thatthe cross bar 68 is designed to cover the aperture 55 during theadvancing operation such that the new frame will not be projected on thescreen until the member is released.

It will now be appreciated that the advance mechanism engages the filmonly during the advancing operation. At all other times the film iscompletely free of the mechanism and may be fed through the assembly andframed merely by inserting and adjusting the film from above. Also, thisfeature protects the film from damage should it be given a sudden pullin either direction, as might be done by a child.

A conventional focusing lens is supported by a housing 81 which issuitably secured in the case. The interconnection between the lens andhousing, as shown for example in FIG. 3, provides a simple, pushpullfocusing system.

The projector is supported by a curved stand 86 which doubles as anelevating device and carrying handle. The stand may be made from asingle piece of chrome-plated steel rod which is suitably'formed or bentinto the desired final shape. The stand 86 is joined to the case of theprojector by a connecting structure which includes a cylindrical ear 82positioned on each side wall 13 adjacent the rear of the projector, anda clamp 83 positioned on each side wall adjacent the front of theprojector. The clamp 83 includes a lip 84 for engaging the stand, and isreleasably connected to the case by means of a threaded knob 85 whichengages a nut 79 permanently secured in the case.

A portion of the stand 86 is positioned on each side of the projector,the two portions being identical in shape and joined by a connectingsegment across the top of the projector. The free end of the stand oneach side of the case is formed into the shape of a cylindrical loop 87which is adapted to be rotatably mounted on and retained by the ear 82.

Adjacent the loop 87 is a vertical segment 88 extending downwardly asufficient distance to lift the case from the supporting structure ortable. Next is a horizontal segment 89 which extends for a distancecomparable to the overall length of the projector and which is designedto rest upon the supporting table. The opposite end of the horizontalsegment 89 is joined to an arcuate segment 90 which is formed into asection of a circle having a center which corresponds to the center ofthe cylindrical loop 87. The arcuate segment 90 extends above theprojector and is joined to the arcuate segment of the opposite side ofthe case by a connecting segment 91 which also serves as a carryinghandle for the projector.

As will be seen in FIG. 2, the lip 84 of the clamp presses the arcuatesegment 90 of the stand against the body of the case to lock the standin position when the knob 85 is tightened. When the knob 85 is loosened,the clamp releases the stand for rotation about the axes of thecylindrical ears 82. By this arrangement, the inclination projector mayeasily be adjusted anywhere between the horizontal and an angle ofapproximately 30. If desired, a rubber feet 92 may be positioned on thehorizontal segment 89 of the stand to increase the frictional contactbetween the stand and its supporting table.

While a specific embodiment of this invention has been disclosed inconsiderable detail herein, it should be understood that the scope ofthe invention is to be determined by that of the following claims only.

What is claimed'is:

l. A projector comprising, an outer case having a pair of opposed sidewalls, opposed upper and bottom up and around opposite sides of the lampand adjacent the side walls and upwardly out of the case through theupper wall, said first air deflecting means being located between thelamp and said side walls and spaced from said side walls, second airdeflecting means to cause a second flow of air from around the upper endof the lamp, rearwardly out of the case at the rear end of the case,means in the case and spaced rearwardly of the front wall of the case,and disposed forwardly of the lamp, to form a passageway disposedtransversely of the case and passing through a pair of said opposedwalls of said case, and formed with a film framing opening, for film topass through the case and past said film framing opening, to frame lightemanating from the lamp and passing through a frame of the film at saidframing opening, to project an image of said frame forwardly.

2. The combination of claim 1, and a stand, means on the stand forsupporting the case on a supporting surface, at various adjusted anglesabout a horizontal transverse pivotal axis through which a lineperpendicular to the center of said framing opening, passes.

3. The combination of claim 2, and lens means in the casing and coaxialwith said line.

4. The combination of claim 3, said lens means comprising a condensinglens assembly disposed between said passageway and lamp support means.

5. The combination of claim 4 and a focusing lens assembly disposedforwardly of said passageway forming means and passing through saidfront wall.

6. The combination of claim 2, said case comprising upper and lowersymmetrically disposed case sections having mutually contacting edges inthe plane of said line and transverse pivotal axis.

7. The combination of claim 1, and means for manually advancing the filmin said passageway, one film at a time.

8. The combination of claim 1, said advancing means including a manuallyengageable actuator member projecting from said case.

9. The combination of claim 8, said passageway forming means comprisinga plate, said side walls of said case having registering slots at saidedges, to receive parts of said plate, said actuating member beingslidably mounted on said plate.

10. The combination of claim 1, said case having a rear opening at itsrear end, and means to mount said lamp support means on the case formovement through said rear opening without disconnecting said lampsupport means from the case, to permit replacement of the lamp.

11. The combination of claim 10, said lamp support means having means toclose the rear opening of said case, when said lamp support means ismoved into said case.

12. A projector comprising an outer case having a pair of side walls, anupper wall, a bottom wall, a front wall and a rear end, means forsupporting an electric lamp within the case adjacent the rear end ofsaid case, means to form a passageway through the case and spacedrearwardly of the front wall, said passageway having a film framingopening, means to feed film through said passageway one frame at a time,past said film framing opening to frame light emanating from the lampand passing through the framed frame of the film, to project an image ofsaid frame forwardly, said passageway forming means providing saidpassageway through said upper and bottom walls of said case and betweensaid side walls, means on the stand for supporting the case on ahorizontal supporting surface, for pivotal movement to various adjustedangles about a transverse horizontal pivotal axis through which a lineperpendicular to the center of the framing opening, passes, condensinglens means in the casing and between said passageway and the lampsupport means, said condensing lens means being coaxial with the centerof said framing opening and perpendicular to said opening said casecomprising upper and lower case sections having mutually contactingedges in a plane passing through the axis of said condensing lens meansand said center of said framing opening and of said pivotal axis.

13. The combination of claim 12, said case having an opening at its rearend, means to mount said lamp support means on the case for movementthrough said rear opening without disconnecting said support means fromthe case, to permit replacement of the lamp, said lamp support meanshaving means to close said rear opening of said case, when said supportmeans is moved into the case.

14. The combination of claim 16, and a focusing lens assembly disposedforwardly of said passageway forming means and passing through saidfront wall of said case.

15. The combination of claim 12, said pair of opposed walls throughwhich said passageway passes being the upper and bottom walls of saidcase.

' I. l k '0' I.

1. A projector comprising, an outer case having a pair of opposed sidewalls, opposed upper and bottom walls, a front wall and a rear end,means for supporting an electric lamp within the case and adjacent therear end of the case, first air deflecting means to cause a first flowof air into the case through the bottom wall, up and around oppositesides of the lamp and adjacent the side walls and upwardly out of thecase through the upper wall, said first air deflecting means beinglocated between the lamp and said side walls and spaced from said sidewalls, second air deflecting means to cause a second flow of air fromaround the upper end of the lamp, rearwardly out of the case at the rearend of the case, means in the case and spaced rearwardly of the frontwall of the case, and disposed forwardly of the lamp, to form apassageway disposed transversely of the case and passing through a pairof said opposed walls of said case, and formed with a film framingopening, for film to pass through the case and past said film framingopening, to frame light emanating from the lamp and passing through aframe of the film at said framing opening, to project an image of saidframe forwardly.
 2. The combination of claim 1, and a stand, means onthe stand for supporting the case on a supporting surface, at variousadjusted angles about a horizontal transverse pivotal axis through whicha line perpendicular to the center of said framing opening, passes. 3.The combination of claim 2, and lens means in the casing and coaxialwith said line.
 4. The combination of claim 3, said lens meanscomprising a condensing lens assembly disposed between said passagewayand lamp support means.
 5. The combination of claim 4 and a focusinglens assembly disposed forwardly of said passageway forming means andpassing through said front wall.
 6. The combination of claim 2, saidcase comprising upper and lower symmetrically disposed case sectionshaving mutually contacting edges in the plane of said line andtransverse pivotal axis.
 7. The combination of claim 1, and means formanually advancing the film in said passageway, one film at a time. 8.The combination of claim 1, said advancing means including a manuallyengageable actuator member projectiNg from said case.
 9. The combinationof claim 8, said passageway forming means comprising a plate, said sidewalls of said case having registering slots at said edges, to receiveparts of said plate, said actuating member being slidably mounted onsaid plate.
 10. The combination of claim 1, said case having a rearopening at its rear end, and means to mount said lamp support means onthe case for movement through said rear opening without disconnectingsaid lamp support means from the case, to permit replacement of thelamp.
 11. The combination of claim 10, said lamp support means havingmeans to close the rear opening of said case, when said lamp supportmeans is moved into said case.
 12. A projector comprising an outer casehaving a pair of side walls, an upper wall, a bottom wall, a front walland a rear end, means for supporting an electric lamp within the caseadjacent the rear end of said case, means to form a passageway throughthe case and spaced rearwardly of the front wall, said passageway havinga film framing opening, means to feed film through said passageway oneframe at a time, past said film framing opening to frame light emanatingfrom the lamp and passing through the framed frame of the film, toproject an image of said frame forwardly, said passageway forming meansproviding said passageway through said upper and bottom walls of saidcase and between said side walls, means on the stand for supporting thecase on a horizontal supporting surface, for pivotal movement to variousadjusted angles about a transverse horizontal pivotal axis through whicha line perpendicular to the center of the framing opening, passes,condensing lens means in the casing and between said passageway and thelamp support means, said condensing lens means being coaxial with thecenter of said framing opening and perpendicular to said opening saidcase comprising upper and lower case sections having mutually contactingedges in a plane passing through the axis of said condensing lens meansand said center of said framing opening and of said pivotal axis. 13.The combination of claim 12, said case having an opening at its rearend, means to mount said lamp support means on the case for movementthrough said rear opening without disconnecting said support means fromthe case, to permit replacement of the lamp, said lamp support meanshaving means to close said rear opening of said case, when said supportmeans is moved into the case.
 14. The combination of claim 16, and afocusing lens assembly disposed forwardly of said passageway formingmeans and passing through said front wall of said case.
 15. Thecombination of claim 12, said pair of opposed walls through which saidpassageway passes being the upper and bottom walls of said case.